Despite all precautionary measures in the design, the construction and operation of gas turbines, fuel leakages of liquid or gaseous fuel in gas turbines guarantee a great risk. If they are not detected in good time, then larger quantities of fuel can escape in an uncontrolled manner, can ignite, and combust or explode with catastrophic consequences.
In order to detect fuel leakages, oil-detecting cables, oil-detector matrices and gas sensors or gas sniffers are known. Extensive monitoring of a ramified fuel distribution system between the fuel control valve and the fuel input line into the individual burners of a gas turbine is particularly difficult. Using conventional methods, this is very costly and, depending on the discharge direction of the leakage flow, a leakage can only be detected with a delay.
Instead of gas detection in the direct vicinity of the gas lines, it was proposed in U.S. Pat. No. 6,761,629 to measure the gas concentration at the outlet of a ventilated enclosure for a gas turbine. In this case, depending on the flow rate of the ventilating air, a threshold value for the concentration of a leakage gas is determined and an alarm is generated when the threshold value is exceeded. In this method also, a leakage can only be detected with a delay.